1. Field of the Invention
The present invention relates to technology relating to matrix type plasma display panel (PDP) and more particularly to technology relating to plasma display panel whose drive power supply is automatically adjusted.
2. Description of the Related Art
Conventionally, the drive voltage for a sustain driver and a scan driver has been adjusted by adjusting variable resistance upon shipment so as to secure an amount of margin corresponding to an influence upon the PDP by a change in temperature upon operation, a change of the PDP itself by time passage and the like. More specifically, a voltage adjusting circuit shown in FIG. 6 is inserted during a supply of electric power to the aforementioned driver and the variable resistor R63 is adjusted so as to correct the voltage of an input to an amplifier 60 thereby adjusting the driving voltage.
Conventional technology about the driving circuit of the PDP unit has been disclosed in Japanese Patent Application Laid-Open No. 2000-293135.
However, it takes skill for adjustment of this PDP and therefore there is a limit in reduction of adjustment cost. Further, there is a room in which human error may be induced.
The intensity of illumination is changed by a change in temperature at the time of startup and after long-hour use and this intensity of illumination is changed by a change with time passage of the PDP itself also. However, the change in the intensity of illumination in the PDP cannot be eliminated completely by adjustment of a single time before shipment.
In the above-mentioned Japanese Patent Application Laid-Open No. 2000-293135, the power supply is described only a symbol of the DC power supply in FIG. 3, is not described about a voltage adjusting function.